The properties available to edit in Designer are set in the properties definition file (.prp) in the Central Library folder. Either through Databook or translations, non-common properties can enter a schematic. Given these properties aren't defined to the tool, they are difficult to edit and delete.
This script will look for a prp file. It then scans the components of the design and makes a dictionary of their properties. It will then check the items in that dictionary against the text in the prp file. A few extra checks have been added for system level properties that start with the "@" symbol.
Select a .prp and click the "Generate Non-Common Properties Report" button to generate the report.
The report can be used to update the .prp file through the Property Definition Editor of the Central Library.